The Collaborative International Dictionary of English v.0.48:

Pollock \Pol"lock\, n. [See Pollack.] (Zool.)
   A marine gadoid fish (Pollachius carbonarius), native both
   of the European and American coasts. It is allied to the cod,
   and like it is salted and dried. In England it is called
   coalfish, lob, podley, podling, pollack, etc.
   [1913 Webster]